Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 1 | # |
| 2 | # The stub may be linked into the kernel proper or into a separate boot binary, |
| 3 | # but in either case, it executes before the kernel does (with MMU disabled) so |
| 4 | # things like ftrace and stack-protector are likely to cause trouble if left |
| 5 | # enabled, even if doing so doesn't break the build. |
| 6 | # |
| 7 | cflags-$(CONFIG_X86_32) := -march=i386 |
| 8 | cflags-$(CONFIG_X86_64) := -mcmodel=small |
| 9 | cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 \ |
| 10 | -fPIC -fno-strict-aliasing -mno-red-zone \ |
Ard Biesheuvel | b523e18 | 2015-12-23 10:29:28 +0100 | [diff] [blame] | 11 | -mno-mmx -mno-sse |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 12 | |
Greg Hackmann | 768dd77 | 2017-10-26 14:57:46 -0700 | [diff] [blame] | 13 | cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie |
Nathan Chancellor | 6301a71 | 2018-11-27 10:53:58 -0700 | [diff] [blame] | 14 | cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ |
Alistair Strachan | fb66079 | 2018-12-03 11:40:57 -0800 | [diff] [blame] | 15 | -fno-builtin -fpic \ |
| 16 | $(call cc-option,-mno-single-pic-base) |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 17 | |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 18 | cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt |
| 19 | |
Ard Biesheuvel | b523e18 | 2015-12-23 10:29:28 +0100 | [diff] [blame] | 20 | KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 21 | $(call cc-option,-ffreestanding) \ |
Sami Tolvanen | 2451857 | 2017-05-01 11:08:05 -0700 | [diff] [blame] | 22 | $(call cc-option,-fno-stack-protector) \ |
| 23 | $(DISABLE_LTO) |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 24 | |
| 25 | GCOV_PROFILE := n |
Andrey Ryabinin | 0b24bec | 2015-02-13 14:39:17 -0800 | [diff] [blame] | 26 | KASAN_SANITIZE := n |
Andrey Ryabinin | c6d3085 | 2016-01-20 15:00:55 -0800 | [diff] [blame] | 27 | UBSAN_SANITIZE := n |
Josh Poimboeuf | c0dd671686 | 2016-02-28 22:22:34 -0600 | [diff] [blame] | 28 | OBJECT_FILES_NON_STANDARD := y |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 29 | |
Dmitry Vyukov | 5c9a875 | 2016-03-22 14:27:30 -0700 | [diff] [blame] | 30 | # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. |
| 31 | KCOV_INSTRUMENT := n |
| 32 | |
Ard Biesheuvel | fc37206 | 2016-04-25 21:06:49 +0100 | [diff] [blame] | 33 | lib-y := efi-stub-helper.o gop.o |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 34 | |
| 35 | # include the stub's generic dependencies from lib/ when building for ARM/arm64 |
| 36 | arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c |
| 37 | |
| 38 | $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE |
| 39 | $(call if_changed_rule,cc_o_c) |
| 40 | |
| 41 | lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \ |
| 42 | $(patsubst %.c,lib-%.o,$(arm-deps)) |
Ard Biesheuvel | f4f75ad5 | 2014-07-02 14:54:43 +0200 | [diff] [blame] | 43 | |
Roy Franz | 81a0bc3 | 2015-09-23 20:17:54 -0700 | [diff] [blame] | 44 | lib-$(CONFIG_ARM) += arm32-stub.o |
Ard Biesheuvel | e4fbf47 | 2016-01-10 11:29:07 +0100 | [diff] [blame] | 45 | lib-$(CONFIG_ARM64) += arm64-stub.o random.o |
Ard Biesheuvel | bf45778 | 2015-10-23 16:48:14 +0200 | [diff] [blame] | 46 | CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) |
| 47 | |
Ard Biesheuvel | ddeeefe | 2015-01-12 20:28:20 +0000 | [diff] [blame] | 48 | # |
| 49 | # arm64 puts the stub in the kernel proper, which will unnecessarily retain all |
| 50 | # code indefinitely unless it is annotated as __init/__initdata/__initconst etc. |
| 51 | # So let's apply the __init annotations at the section level, by prefixing |
| 52 | # the section names directly. This will ensure that even all the inline string |
| 53 | # literals are covered. |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 54 | # The fact that the stub and the kernel proper are essentially the same binary |
| 55 | # also means that we need to be extra careful to make sure that the stub does |
| 56 | # not rely on any absolute symbol references, considering that the virtual |
| 57 | # kernel mapping that the linker uses is not active yet when the stub is |
| 58 | # executing. So build all C dependencies of the EFI stub into libstub, and do |
| 59 | # a verification pass to see if any absolute relocations exist in any of the |
| 60 | # object files. |
Ard Biesheuvel | ddeeefe | 2015-01-12 20:28:20 +0000 | [diff] [blame] | 61 | # |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 62 | extra-$(CONFIG_EFI_ARMSTUB) := $(lib-y) |
| 63 | lib-$(CONFIG_EFI_ARMSTUB) := $(patsubst %.o,%.stub.o,$(lib-y)) |
Ard Biesheuvel | ddeeefe | 2015-01-12 20:28:20 +0000 | [diff] [blame] | 64 | |
Ard Biesheuvel | 6b66b2d8 | 2017-01-31 13:21:42 +0000 | [diff] [blame] | 65 | STUBCOPY_RM-y := -R *ksymtab* -R *kcrctab* |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 66 | STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ |
| 67 | --prefix-symbols=__efistub_ |
| 68 | STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS |
| 69 | |
| 70 | $(obj)/%.stub.o: $(obj)/%.o FORCE |
| 71 | $(call if_changed,stubcopy) |
| 72 | |
Ard Biesheuvel | 6b66b2d8 | 2017-01-31 13:21:42 +0000 | [diff] [blame] | 73 | # |
| 74 | # Strip debug sections and some other sections that may legally contain |
| 75 | # absolute relocations, so that we can inspect the remaining sections for |
| 76 | # such relocations. If none are found, regenerate the output object, but |
| 77 | # this time, use objcopy and leave all sections in place. |
| 78 | # |
Ard Biesheuvel | e8f3010 | 2015-10-08 20:02:04 +0100 | [diff] [blame] | 79 | quiet_cmd_stubcopy = STUBCPY $@ |
Ard Biesheuvel | 6b66b2d8 | 2017-01-31 13:21:42 +0000 | [diff] [blame] | 80 | cmd_stubcopy = if $(STRIP) --strip-debug $(STUBCOPY_RM-y) -o $@ $<; \ |
| 81 | then if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); \ |
| 82 | then (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ |
| 83 | rm -f $@; /bin/false); \ |
| 84 | else $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; fi \ |
| 85 | else /bin/false; fi |
Roy Franz | 81a0bc3 | 2015-09-23 20:17:54 -0700 | [diff] [blame] | 86 | |
| 87 | # |
| 88 | # ARM discards the .data section because it disallows r/w data in the |
| 89 | # decompressor. So move our .data to .data.efistub, which is preserved |
| 90 | # explicitly by the decompressor linker script. |
| 91 | # |
Ard Biesheuvel | 6b66b2d8 | 2017-01-31 13:21:42 +0000 | [diff] [blame] | 92 | STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub |
| 93 | STUBCOPY_RM-$(CONFIG_ARM) += -R ___ksymtab+sort -R ___kcrctab+sort |
Roy Franz | 81a0bc3 | 2015-09-23 20:17:54 -0700 | [diff] [blame] | 94 | STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS |